Flash memory efficient LTL model checking

As the capacity and speed of flash memories in form of solid state disks grow, they are becoming a practical alternative for standard magnetic drives. Currently, most solid-state disks are based on NAND technology and much faster than magnetic disks in random reads, while in random writes they are generally not.So far, large-scale LTL model checking algorithms have been designed to employ external memory optimized for magnetic disks. We propose algorithms optimized for flash memory access. In contrast to approaches relying on the delayed detection of duplicate states, in this work, we design and exploit appropriate hash functions to re-invent immediate duplicate detection.For flash memory efficient on-the-fly LTL model checking, which aims at finding any counter-example to the specified LTL property, we study hash functions adapted to the two-level hierarchy of RAM and flash memory. For flash memory efficient off-line LTL model checking, which aims at generating a minimal counterexample and scans the entire state space at least once, we analyze the effect of outsourcing a memory-based perfect hash function from RAM to flash memory.Since the characteristics of flash memories are different to magnetic hard disks, the existing I/O complexity model is no longer sufficient. Therefore, we provide an extended model for the computation of the I/O complexity adapted to flash memories that has a better fit to the observed behavior of our algorithms.     

Prediction of diesel fuel cold properties using artificial neural networks

In this paper, two neural networks, multilayer perceptron and networks with radial-basis function, were used to predict important cold properties of commercial diesel fuels, namely cloud point and cold filter plugging point. The developed models predict the named properties using cetane number, density, viscosity, contents of total aromatics, and distillation temperatures at 10, 50, and 90 vol. % recovery as input data. The training algorithms, number of hidden layer neurons, and number of training data points were optimized in order to obtain a model with optimal predictive ability. The results indicated better prediction of cloud and cold filter plugging points in the case of multilayer perceptron networks. The obtained absolute error mean for the optimal neural network models (0.58°C for the cloud point and 1.46°C for the cold filter plugging point) are within the range of repeatability of standard cold properties determination methods.     

A study on the crystallization of amorphous arsenic

The results of DTA analysis of amorphous arsenic in combination with electron microscopical study of the samples through the whole temperature range reveal that no changes of the initial state of the sample occur on heating up to crystallization temperature. Close above this temperature the spontaneous crystallization starts. It differs markedly from the case of glassy materials, like As₂Te₃, in which case at temperatures as low as the transition region T_g the crystallization nuclei of geometrically defined shapes appear and grow into crystalline grains on further heating.     

MA‐NOTMP: A Triazacyclononane Trimethylphosphinate Based Bifunctional Chelator for Gallium Radiolabelling of Biomolecules

In the past few years, gallium‐68 has demonstrated significant potential as a radioisotope for positron emission tomography (PET), and the optimization of chelators for gallium coordination is a major goal in the development of radiopharmaceuticals. Methylaminotriazacyclononane trimethylphosphinate (MA‐NOTMP), a new C‐functionalized triazacyclononane derivative with phosphinate pendant arms, presents excellent coordination properties for ⁶⁸Ga (low ligand concentration, labelling at low pH even at room temperature). A “ready‐to‐be‐grafted” bifunctional chelating agent (p‐NCS‐Bz‐MA‐NOTMP) was prepared to allow ⁶⁸Ga labelling of sensitive biological vectors. Conjugation to a bombesin_(7–14) derivative was performed, and preliminary in vitro experiments demonstrated the potential of MA‐NOTMP in the development of radiopharmaceuticals. This new chelator is therefore of major interest for labelling sensitive biomolecules, and further in vivo experiments will soon be performed.     

Improved Corners with Multi‐Channel Signed Distance Fields

We propose an extension to the state‐of‐the‐art text rendering technique based on sampling a 2D signed distance field from a texture. This extension significantly improves the visual quality of sharp corners, which is the most problematic feature to reproduce for the original technique. We achieve this by using a combination of multiple distance fields in conjunction, which together provide a more thorough representation of the given glyph's (or any other 2D shape's) geometry. This multi‐channel distance field representation is described along with its application in shader‐based rendering. The rendering process itself remains very simple and efficient, and is fully compatible with previous monochrome distance fields. The introduced method of multi‐channel distance field construction requires a vector representation of the input shape. A comparative measurement of rendering quality shows that the error in the output image can be reduced by up to several orders of magnitude.     

The Bi-Sr-Ca-Cu-(Al)-O system; accompanying phases I

Bulk samples of superconductive cuprates BiSrCaCuO were prepared by melting of mixtures of oxides and carbonates, in alumina crucibles, using various thermal treatments. In some samples, several accompanying non-superconductive phases appeared. The later were studied by visual examination under the optical microscope, scanning electron microscopy, electron microprobe analysis and X-ray diffraction (single crystal precession and powder Gandolfi camera). Besides Bi₂Sr₂CaCu₂O₈ (further 2212) and Bi₂Sr₂CuO₆ (2201) BiSrCaCuO phases, CuO and Ca₂CuO₃ (with Sr content), another phase with composition Bi₄Sr_1.45Ca_2.31Cu_0.37O_10.13 was found in one sample in the form of oriented intergrowths with Cu₂O. The powder diffraction data enabled us to interpret the former compound as Bi₂SrCaO₅ with some Sr replaced by Ca. In addition, a yellow-coloured phase of approximate composition BiSr₂CaAl₃O₉, cubic, F-centred, (for two specimens a = 2.486(6) nm or a = 2.496(8) nm, was found in three samples heated to over 1040°C. This phase resulted from the reaction with the alumina crucible. The X-ray precession and powder data are reported.     

Photoluminescence of Ga0.94In0.06As0.13Sb0.87 solid solution lattice matched to InAs

The lattice matched Ga_0.94In_0.06As_0.13Sb_0.87 quaternary solid solutions were grown by liquid phase epitaxy on (1 0 0) oriented InAs substrates from In rich melt. The p-type GaIn_0.06As_0.13Sb layers were intentionally undoped and their hole concentration was about p5×10¹⁶ cm⁻³, while n-type GaIn_0.06As_0.13Sb layers were slightly doped with Te and their electron concentration was about n10¹⁷ cm⁻³. Photoluminescence spectra exhibit single unresolved emission band in the spectral region from 0.65 to 0.8 eV for both types. Spectra were decomposed to elementary Gaussian components. The main mechanisms of radiative recombination were determined for both types of material.